Vesicovaginal and Ureterovaginal Fistula

Unrecognized bladder injury during a difficult hysterectomy or cesarean delivery may result in vesicovaginal fistula formation. Most vesicovaginal fistulae occur when dissection of the bladder during the mobilization of the bladder flap causes devascularization or an unrecognized tear of the posterior bladder wall. Alternatively, if the vaginal cuff suture was unknowingly incorporated into the bladder, this can result in tissue ischemia, necrosis, and subsequent fistula formation.

The ureter may become injured during the dissection around the infundibulopelvic ligament or ligation of the uterine vessels. Unexpected pelvic hemorrhage may obscure the surgeon's vision and result in ureteral injury that manifests as delayed ureterovaginal fistula. Uncommonly, this can also occur in the setting of an unrecognized duplicated ureter.

Fistulae resulting from vaginal birth occur during difficult or prolonged labor. The head of the fetus compresses the trigone or the bladder neck against the anterior arch of the pubic symphysis. This may result in tissue ischemia, necrosis, and eventual fistula formation. Currently, this is rare in the United States; however, it remains common throughout much of the world.

In the United States, more than 50% of vesicovaginal and ureterovaginal fistulae occur after hysterectomy for benign diseases such as uterine fibroids, menstrual dysfunction, or uterine prolapse. 

Pelvic radiation is the primary cause of delayed fistula, which can occur from one month to many years after the initial radiation treatment. Radiation therapy is typically used to treat cervical or endometrial carcinoma. Vesicovaginal fistulae and ureterovaginal fistulae may occur with or without cancer recurrence.

In countries with limited resources, obstetrical complications are the most common cause of vesicovaginal and ureterovaginal fistulae. This may develop in cases of long-standing and obstructed labor leading to pressure necrosis on the anterior vaginal wall. Fistulae in this setting may be large and involve extensive local tissue damage and necrosis.

A systematic review over a 35-year period reported that 83.2% of fistula in developed countries were iatrogenic, whereas 95.2% of fistula in developing countries were the result of obstetric complications.[4]  However, the incidence of vesicovaginal fistula resulting from hysterectomy is estimated to be less than 1%. Approximately 10% of such fistulae may involve one or both ureters. Some fistulae may be more complex, involving adjacent organs. If the rectum is involved in the inflammatory reaction, rectovaginal fistulae may develop.[9]

The estimates of the global prevalence of untreated obstetric fistula vary from 654,000 to 3,500,000. In Ethiopia, Malawi, and Bangladesh, reported incidences range between 1.5 and 1.7 per 1000 women. An estimated 33,451 new cases occur annually in rural sub-Saharan Africa. Hospital-based reports show the incidence to be between 0.6 and 6.5 per 1000 births.[10]

The success rate of vesicovaginal and ureterovaginal fistula repair approaches 90% at first attempt and approaches 100% after a second attempt.[11, 12] However, the second operation is more extensive and more complex than the first operation. Often, the surgical approach must be changed, and additional procedures (eg, Martius flap, peritoneal flap, omental flap, or gracilis muscle flap) must be performed in combination with the fistula repair. For complex repairs involving irradiated tissues, the success rate is less than 90%, but, for experienced surgeons, the outcome remains highly successful.

Keep in mind that the first operation is the best one. Any attempts at further surgical repair after an initial failed approach may yield unsatisfactory results. To maximize outcomes and minimize further potential morbidity, it is highly recommended to seek out a surgeon who is adept at this type of reconstruction and performs it in a high volume.

Suspect a possible fistula when a patient reports acute onset of urinary incontinence after recent gynecologic surgery (eg, hysterectomy or cesarean delivery), if the degree of incontinence is disproportional to the physical findings, or if the medical history and the nature of incontinence are inconsistent. If a fistula is small, the incontinence may mimic stress urinary incontinence. 

The clinical history of vesicovaginal or ureterovaginal fistula is usually straightforward. Typically, a gynecologic procedure, such as hysterectomy, is involved. Often, the operation is reported to have been technically challenging. Poor intraoperative exposure, coupled with heavy bleeding at the operative site, are often risk factors. An associated bladder or ureteral injury may have occurred and may have been repaired.

Patients with vesicovaginal fistula often report painless unremitting urinary incontinence. This is also called total, or continuous, incontinence requiring the use of several thick pads per day. The urinary incontinence mimics stress incontinence, in which urine loss is more dramatic during physical activities or when the individual stands upright from a lying position. Symptoms of urinary frequency and urgency are typically absent. Patients may notice a clear vaginal discharge

Acute onset of vesicovaginal fistula immediately after pelvic surgery does not cause constitutional symptoms. If the Foley catheter is still in place, the first sign of impending fistula formation is the presence of hematuria.

Conversely, patients with ureterovaginal fistula may experience constitutional symptoms of fever, chills, malaise, flank pain, and gastrointestinal symptoms in association with continuous urinary incontinence. Constitutional symptoms may result from hydronephrosis secondary to ureteral obstruction or urinary extravasation into the retroperitoneal space. Acute-onset ureterovaginal fistulae are often associated with a difficult postoperative course. These patients present with fever, ileus, and abdominal and flank pain.

Approximately 10-15% of fistulae do not manifest clinically for 10-30 days after the inciting procedure. Some fistulas may not manifest for months. Radiation-induced fistulae may not become apparent for many years after radiation treatment. The development of a typical radiation-induced fistula is heralded by radiation cystitis, hematuria, and bladder contracture. These symptoms are improved dramatically by the sudden presence of vesicovaginal fistula.

On physical examination, patients with new-onset ureterovaginal fistulae may demonstrate flank or abdominal tenderness due to hydronephrosis and/or urinary extravasation into the retroperitoneal space. Patients with vesicovaginal fistulae do not present with abdominal or flank symptoms.

A detailed pelvic examination reveals clear fluid pooling at the apex of the vagina. This fluid should be collected for evaluation of creatinine level. On close inspection, a pinpoint opening at the vaginal apex is often visible in patients with mature fistulas. When a fistula has not yet matured (immature fistula), the vaginal mucosa is inflamed and erythematous, with granulation tissue surrounding the fistulous tract. The fistulous opening is often difficult to localize in immature fistulas.

Patients with fistulae may tolerate pelvic examination poorly, further complicating the assessment. In these situations, pelvic examination under general anesthesia is warranted. In addition, involvement of a urologist for performance of cystoscopy with retrograde pyelograms should be encouraged. 

If the presence of a vesicovaginal or ureterovaginal fistula is in doubt, vaginal secretions and fluid pooling in the vaginal vault should be sent for creatinine level evaluation. Serum creatinine should be drawn simultaneously, and if the fluid creatinine level is significantly higher than the serum creatinine, this confirms that the fluid is urine. If fluid creatinine test result is equivocal but a fistula is still suspected, proceed with a complete fistula workup, as discussed below.

Additional tests are as follows:

• Urinalysis and urine culture, to rule out coexisting urinary tract infection
• Basic metabolic panel (Chem 7), to evaluate kidney function
• Complete blood cell count (CBC), to rule out systemic infection

Radiographic imaging should include intravenous pyelography (IVP) or computed tomography (CT) urography to rule out coexisting ureterovaginal fistula or ureteral obstruction. When a ureter is involved in the margin of the vesicovaginal fistula, IVP may demonstrate a standing column of contrast within the ureter, extravasation of contrast around the distal ureter, or hydronephrosis.

Cystography often demonstrates contrast leaking from the fistula tract (see image below). This confirms the presence of vesicovaginal fistula.   Similarly, a retrograde pyelogram can demonstrate the presence of a ureterovaginal fistula. 

Methylene blue dye test

In patients who are suspected to have a vesicovaginal fistula, a methylene blue dye test can be performed, which has excellent specificity and is likely to be positive in diagnosis of fistula. Methylene blue is infused intravenously and a tampon is placed within the vagina. If the tampon turns blue, the test is positive for a vesicovaginal fistula. 

Double dye test

Frequently, the double dye test is useful for diagnosing vesicovaginal and ureterovaginal fistulae. In this test, the patient ingests oral phenazopyridine (Pyridium), and indigo carmine or methylene blue is instilled into the bladder via a urethral catheter. Pyridium turns urine orange, and methylene blue (or indigo carmine) turns urine blue. A tampon is placed into the vagina. If the tampon turns blue, suspect vesicovaginal fistula. If the tampon turns orange, suspect ureterovaginal fistula. If the tampon turns blue and orange, suspect a combination of vesicovaginal and ureterovaginal fistulas.

 

 

Cystoscopy

Cystoscopy with concurrent vaginal speculum examination helps determine the location and size of the fistula in relation to the vaginal cuff, trigone, and ureteral orifices. In addition, it reveals the degree of inflammatory reaction and the number of fistulas present. Most fistulas discovered after hysterectomy are located immediately behind the interureteric ridge and on the anterior vaginal vault.

Retrograde pyelography

This is the most definitive test to determine the presence of ureterovaginal fistula. Retrograde pyelography must be performed if IVP findings are abnormal or if the fistula site is difficult to locate. Performing bilateral retrograde ureteropyelography is often important because both ureters may be injured.

If the fistulous tract is excised as part of the repair technique, the specimen should be sent for pathologic evaluation to review the histologic findings. Pathologic findings vary depending on the cause of the fistula and may include foreign body,[13] giant cell reaction, malignancy, or chronic inflammation.

Giant cell reaction may be present if a foreign body was part of the cause of the fistula (eg, a nonabsorbable suture ligature of a uterine vessel catching the vaginal cuff and the bladder wall).

Radiation-induced fistulae are due to late changes caused by the radiation. After cessation of radiation therapy, fibrosis occurs in the bladder lamina propria. As fibrosis occurs in the subepithelial tissues, hyalinization of the connective tissues occurs. Often, large bizarre fibroblasts (ie, radiation fibroblasts) are encountered. An obliterative arteritis may be observed in medium-to-small vessels. These vascular changes may result in atrophy or necrosis of the bladder epithelium, causing ulceration or the formation of fissures. Again, it is important to rule out local cancer recurrence, especially in the setting of prior radiation therapy.

With fistulae due to cervical carcinoma, pathologic examination may demonstrate squamous cell carcinoma or adenocarcinoma. Fistulae due to iatrogenic injury manifest as signs of acute and chronic inflammation. The presence of abundant neutrophils suggests an acute inflammatory response. In patients with chronic inflammation, the predominantly lymphocytic infiltrate is associated with macrophages. In addition, interstitial tissue fibrosis and necrosis may be present.

No medical therapy is available for the management of vesicovaginal and ureterovaginal fistula. However, conjugated estrogen (oral or transvaginal) helps vaginal tissues become softer and more pliable for upcoming fistula repair. This is especially important for postmenopausal women and women with atrophic vaginitis.[14]

For personal hygiene and skin care, sitz baths with a solution of permanganate or baking soda douches may be helpful.

For a small fistula, an initial trial of urethral catheter drainage may be attempted for 4-6 weeks. However, catheter drainage and/or fulguration of the edges of the fistula tract less often results in a cure. Small fistulae have a higher likelihood of healing with catheterization. In the rare series of patients who were successfully managed with fulguration, optimal results were achieved in patients who had longer and narrower fistulas, as opposed to short and wide ones. Similarly, ureteral stents can result in spontaneous closure of ureterovaginal fistulae, particularly in the setting of small, non-radiation associated fistulae. 

Vesicovaginal and ureterovaginal fistulae recognized within 3-7 days after the causative operation may be repaired immediately via a transabdominal or transvaginal approach. Fistulae identified after 7-10 days postoperatively should be monitored periodically until all signs of inflammation and induration have resolved. Before embarking on fistula repair, the fistula tract should be well epithelialized and the vaginal wall should be soft and supple.

In the past, surgical repair of any vesicovaginal fistula before 3 months was discouraged for fear of recurrence and inadequate healing. However,  the principle of delayed repair is no longer absolute. The timing of fistula repair is now dictated by the nature of the local tissues around the fistula site. Surgical repair may commence if no vaginal infection is present and if the inflammatory process at the fistula site has resolved. Some surgeons have successfully closed fistulae with or without using a tissue interposition, such as Martius flap or peritoneal flap, without waiting 3-4 months. The main concern with early intervention is that satisfactory tissue quality and healing must be evident or the surgery may not have a satisfactory result.

Patients with a history of multiple failed repairs, patients with associated enteric fistula with pelvic phlegmon, and patients with a history of pelvic radiation should not undergo fistula repair for at least 6-8 months.

The presence of an active vaginal infection or persistent inflammatory or malignant process at the fistula site is a contraindication to surgical repair. Historically, the transvaginal approach has been contraindicated for supratrigonal fistulae. However, this is no longer an absolute contraindication. Whether to use a transabdominal or transvaginal approach is now dictated by the surgeon's experience and preference and ease of access to the fistula site.

Use of platelet-rich plasma (PRP) as both a novel primary treatment for closure of vesicovaginal fistula and as an adjuvant treatment to improve surgical wound healing have shown promising outcomes in reported cases and small series.[15, 16, 17]

The main goal in correcting vesicovaginal fistula is to separate the fistulous communication between the bladder and the vagina. This can be accomplished by inserting interposing tissue between the 2 organs and obtaining a watertight tension-free closure.

Pinpoint fistulae may respond to conservative management with urethral catheter drainage and fulguration of the fistulous tract, but success rates may be low. Persistent incontinence after an adequate period of watchful waiting requires open exploration and formal fistula repair.

Historically, the site of the fistula and surgeon familiarity often dictated the surgical approach. Supratrigonal fistulas (fistulas above the interureteric ridge) were typically approached transabdominally. Infratrigonal fistulas (fistulas below the interureteric ridge) were corrected transvaginally.

A history of previous failed repairs does not preclude transvaginal reconstruction. Fistulae located in the infratrigonal area, fistulae near the bladder neck, and those occurring after hysterectomy are usually amenable to transvaginal reconstruction. Transvaginal repairs do not require excision of the fistula tract.[18]

In corrections of extensive fistulae after radiation therapy, a combined transvaginal and transabdominal approach with fixation of the omentum or peritoneal flaps in the space between the vagina and urinary bladder is often useful. Increasingly, this is being done with minimally invasive techniques, laparoscopically or robotically.[19, 20, 5]  However, there have been no large studies that compare transvaginal repair to minimally invasive transabdominal approaches.[21]

Ureterovaginal fistulae may be treated with an internal stent and often will close spontaneously.[11] However, persistent fistulas despite stent placement warrant surgical exploration and ureteral reimplantation either through an open or minimally invasive approach.

It is important to note that the basic rule for fistula repair is that the first operation has the best chance of success, and surgeons should use the approach with which they feel most comfortable. All adjuncts should be included to ensure successful closure of the fistula.

Images of repair techniques are depicted below.

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Informed consent discussions should include potential risks. These include, but are not limited to, the following:

• Ureteral injury
• Bladder injury
• Bowel injury
• Recurrence of fistula
• Persistent fistula
• Sexual dysfunction
• De novo urinary dysfunction
• Bleeding
• Infection

Inform the patient if a Martius fat pad or gracilis muscle flap will be used.

Postoperatively there may be long-term impact on sexual function and urinary continence even after a successful repair, defined as anatomical closure. The most common reasons cited for sexual dysfunction include urinary incontinence and pain with intercourse. A large fistula (> 3 cm) and decreased vaginal caliber are associated with the highest rate of sexual dysfunction.[7]  Although a transvaginal approach is thought to shorten the vagina, sexual dysfunction appears to be similar in transvaginal and transabdominal repaired fistulae. Patients may develop de novo urinary urge or stress incontinence.[7, 8]  

Preexisting urinary tract infection should be cleared, and preoperative conjugated estrogen therapy is helpful. Broad-spectrum intravenous antibiotics are administered preoperatively.

Vesicovaginal Fistula Repair

Vesicovaginal fistulae can be repaired via a transvaginal, transabdominal, or laparoscopic and robotic approaches.

Transvaginal approach

Place the patient in a dorsal lithotomy position. Insert a percutaneous suprapubic tube and urethral catheter. Insert a posterior-weighted vaginal speculum and place a self-retaining vaginal retractor.

Identify the fistula and place traction sutures on the vaginal mucosa next to the fistula site. For traction, a small urethral catheter (8F) is inserted into the fistula. If the tract is very small, dilate the fistula to an acceptable size for urethral catheter insertion. The use of Fogarty balloon catheters and expensive catheters is unwarranted and adds unnecessarily to the expense of the procedure, as a regular (albeit smaller) Foley catheter usually suffices.

Using an inverted J-shaped incision, circumscribe the fistula site. Dissect the anterior vaginal wall off the underlying pubocervical fascia. Close the fistula tract (bladder mucosa) vertically using 2-0 or 3-0 absorbable sutures in a watertight fashion. Close the pubocervical fascia using 2-0 or 3-0 absorbable sutures horizontally. An additional layer of peritoneal-based flap from the posterior incision can be placed as a third layer. Excise the redundant vaginal mucosa. Approximate the vaginal incision using 2-0 absorbable sutures, without causing an overlapping suture line. Place Betadine-soaked packing in the vagina.

Alternatively, a Latzko partial colpocleisis technique can be used. In this technique, 2 concentric circular incisions around the fistula tract are made. The vaginal mucosa is excised in quadrants. The fistulous tract, pubocervical fascia, and vaginal mucosa are closed in layers, without overlapping suture lines.

When closure is difficult or tenuous, a Martius fat pad (pedicle flap) may be harvested from the labia majora and interposed. A cylindrical bundle of bulbocavernosus and pedicled fat are developed carefully, preserving the superior external pudendal artery. A capacious tunnel under the vaginal mucosa between the labia majora and the fistula site is then developed. The labial pedicle flap is brought through the vaginal mucosal tunnel and sutured to the edges of the fistula repair. The vaginal mucosa then is closed over the fat pad.

Transabdominal approach

Place the patient in a modified lithotomy position or supine depending on surgeon preference. Insert a urethral catheter. Make an infraumbilical incision and carry it down into the peritoneal cavity. Expose the pouch of Douglas. Completely mobilize the bladder and bivalve it at the dome. Identify the ureteral orifices and the fistula tract.

Cannulate both ureteral orifices with pediatric feeding tubes for easy identification. Circumscribe and excise the fistula. Separate the bladder from the vagina. Close the bladder with sequential 2-0 or 3-0 absorbable sutures after the vaginal closure is completed.

If omental interposition is performed, the abdominal incision should be carried to the epigastrium, with mobilization of the omentum. Separate avascular adhesions to the transverse colon. Divide and ligate the left gastroepiploic and short gastric vessels. Mobilize the omentum using the right gastroepiploic pedicle. Medially mobilize the ascending colon and hepatic flexure. Pass the omentum, which is hinged on the right gastroepiploic artery, behind the ascending colon and into the pelvis.

Close the vagina using 2-0 absorbable sutures. Suture the distal aspect of the omentum to the distal limits of the space between the vagina and the bladder. Complete the bladder closure in 1-2 layers. Put the suprapubic tube and pelvic drains in place.

If ureteral reimplantation is necessary, dissect out the ureter prior to fistulectomy. Reimplant the ureter in the upper bladder wall after the fistula is closed with or without adjunct procedures such as a psoas hitch or boari flap. The ureter should be stented postoperatively.

Laparoscopic and robotic approaches

In the era of more minimally invasive management (MIS), increasing experience in the use of robotic and laparoscopic technologies has yielded successes with vesicovaginal fistulae repairs.[22, 23]  Adherence to similar principles as in open abdominal repair with use of interposition grafts and layered closures has produced reports of successful repair. Often, there is a fair amount of scarring and extravasation in the area of the fistula, which may affect the quality of the repair. Nonetheless, the use of MIS technology for this type of repair is increasing.[21]

Successful laparoscopic repair of a recurrent vesicovaginal fistula using the transvesical approach guided by cystoscopy has been reported.[24]

Ureterovaginal Fistula Repair

Position the patient in dorsal lithotomy or supine position based on surgeon preference and make a lower midline incision. Dissect out the ureter and trace this distally to the bladder. Dissect the bladder off of the vagina to ensure that the ureterovaginal fistula has been fully exposed. Transect the ureter as distally as possible. Closure of the distal ureter at the bladder can be performed with an absorbable or permanent suture such as a 2-0 silk tie. Closure of the vaginal side of the fistula can be performed using 2-0 or 3-0 absorbable suture. An interposition flap can be placed using omentum, peritoneum, or gracilis muscle. The ureter then requires reimplantation into the bladder with or without psoas hitch. Stenting is recommended for 4-6 weeks following the reimplantation.  

Continue intravenous antibiotics for at least 24 hours perioperatively . To prevent bladder spasms, prescribe anticholinergics or beta adrenergic medications.  Pelvic drains can be tested for a urine leak prior to removal prior to discharge from the hospital.  

Many surgeons choose to keep a urethral catheter in place for 2-3 weeks and any stent for a ureterovaginal fistula repair in place for 4-6 weeks. 

 

Potential complications associated with repairing large vesicovaginal and ureterovaginal fistulae include the development of transient vesicoureteral reflux or de novo detrusor instability. Reflux and bladder spasms often resolve spontaneously with anticholinergic or beta-adrenergic therapy.

If a large fistula is present, the nearby ureteral orifice is at risk of becoming obstructed during the repair. If this is the case, the ureter must be reimplanted during the initial operation. The most feared complication is the recurrence of fistula. If this occurs, a proper waiting period is advised. The subsequent repair should be performed with a Martius flap, peritoneal interposition, or gracilis muscle flap.

Complications associated with ureterovaginal fistula repair include urinary extravasation and ureteral stricture formation. Persistent urinary leak can be treated with percutaneous nephrostomy drainage, ureteral stent(s), and/or Foley catheter drainage. For short ureteral strictures, minimally invasive endoscopic treatments can be used.

Remove the urethral catheter and perform cystography 2-3 weeks following surgery. Alternatively, intravesical methylene blue may be used. If extravasation is not evident, the suprapubic tube may also be removed. If a persistent leak is present, leave the suprapubic tube in place and perform cystography 2 weeks later. When the cystogram does not define extravasation, the suprapubic tube may be removed.